Environmental correlates of some selected fish species in the Jebba Dam, North-Central Nigeria

There is a lack of comprehensive understanding of environmental factors influencing fish species’ abundance and distribution in some Nigerian freshwater ecosystems. Our study investigated the environmental factors that drive the abundance and distribution of three economically important fishes – Lates niloticus, Citharinus citharus, and Distichondus rostratus – in Jebba Hydroelectric power dam in Northcentral Nigeria. The species catch abundance was determined using gillnets of different mesh sizes, each measuring 50 m length and 20 m deep. The physicochemical parameters were also assessed following standard methods. A total relative abundance of 47.49%, 27.74%, 24.77% were observed for C. citharus, L. niloticus, and D. rostratus, respectively. The canonical correspondence analysis showed that the catch abundance of L. niloticus associates with water volume, turbidity, phosphate, and hydrogen carbonate. Analysis showed that water hardness, biological oxygen demand (BOD), dissolved oxygen (DO), and chloride levels drive the catch abundance of D. rostratus, while C. citharus associates with temperature and depth. The linear Pearson correlation showed a strong positive relationship of the abundance of L. niloticus with turbidity, phosphate, total suspended solids, hydrogen carbonate, water depth, temperature, and water volume. Our result showed a strong positive association of the abundance of C. citharus with water volume, total dissolved solids, temperature, and water depth. A strong positive relationship of the abundance of D. rostratus with conductivity, water depth, and total dissolved solids was reported. Our study improved knowledge on the environmental factors affecting the abundance of three economically important freshwater fishes in Jebba Hydroelectric dam. Further study is needed to investigate the impact of global climate change on the future distribution of these freshwater fish species.